Sewing machine



' SEWING MACHINE Filed April 16, 1941 v:5 Sheets-Sheet 1 \NVENTOR ATTORNEY fziznvy Z57 C v July 20, 1943. CLAYTON 2,324,558

SEWI1!G MACHINE Filed April 16, 1941 s Sheets-Sheet 2 ATTORNEY July 20, 1943. H.. E. CLAYTON SEWING MACHINE Filed April 16, 1941 3 Sheets-Sheet 3 INVENTOR E Cfqyforz .Hca-vy BY do.

ATTORNEY Patented July 20, 1943 UNITED sTATEs PATENT OFFICE Harry E. Clayton, Holland, N. in, asslgnor, t,

mesne assignments, to Bagpak, Inc., a corporation oi Delaware Application April 16, 1941, Serial No. mm

1 11 Claims. 112-191) This invention relates to new and useful improvements in sewing machines and particularly seeks to provide novel stitch forming mechanisms adapted to form a double thread chain stitch employing anauxiliary binder thread of the type 5 disclosed in my copending application, Serial No. 383,483, filed March 15, 1941. l

The stitch forming mechanisms which comprise this invention are particularly adapted to be employed in connection with sewing machines of the general type disclosed in U.-S. Letters Patent 2,043,149, granted to Howland F. Briggson June 2, 1936 but obviously may be employed in connection with other suitable forms 01' sewing machines.

' Heretoiore, when filled paper bags or the like have been closed and sealed by the formation of a line oi stitches across the formed closure, various forms of seams have been employed as well as various types of stitch formations. It has been known to employ a single thread chain stitch to secure the bag closur e in its completely folded position wherein the collapsed bagmouth is folded back upon itself or to employ a double thread chain stitch for the same purpose. in the instances where the single thread chain stitch was employed, it has been observed that neither the thread entering the work on the needle side .nOr the interconnected loops on the work support side were so disposed or so proportioned that the apertures formed by the passage of the needle through the work were substantially sealed. Thus, a stitch closing 01 these forms of bag closures present difliculties in maintaining the bags in a sift-proof condition. In those types of stitched bag closures which employed the double thread chain stitch, it has been observed that substantially the same condition held true but to a somewhat'less degree since the second series oi. interconnected loops formed by the looper thread 40 of the double thread chain stitch provided a reasonably efiective means for sealing those sides of the needle apertures which were presented towards the worksupport.

The above "mentioned difliculties in connection with the formation of stitched bag closures through the employment ofeither single thread or double thread chain stitches have been overcome throughthe use of a modified double thread chain stitch formed through the use oi mechanisms constructed in accordance with this invention and by which both ends of each" individuel needle aperture formed in the work are substantially sealedby certain portions oigthe loops comprising the stitches It is therefore an object of this invention to provide in a sewing machine novel mechanisms eiIective to form a stitch of the double thread chairf stitch type which employs an auxiliary or binding thread serially formed into a plurality of spaced loops located upon the needle side of the work and encompassing the base portion of each needle thread loop.

Another object 01. this inventionis to provide a sewing machine of the character stated which includes a pair of cooperatively disposed loop forming elements located on the needle side of themachine and'efiective to form spaced loops in the auxiliary or binding thread.

Another object of this invention is to provide a machine of the character stated in which the cooperatively disposed loop forming elements are operatively connected with the main drive shaft of the sewing machine with which they are associated.

Another object of this invention is to provide a machine 01 the character stated which i effective to form a line of stitches oi the double thread chain stitch type employingan auxiliary or binding thread on the needle side of the work and in which the loops oi. the auxiliary thread will substantially plug the needle apertures on the needle side 01' the work and theconcatenated loops of the needle and looper threads will substantially plug the apertures of the work on the work support side.

ence to the dra'wings,.th accompanying detailed description, and the appended claims. i In the drawings:

formed by mechanisms constructed in accordance with this invention and taken from theneedle side oi the work;

Fig. 2 is a horizontal section taken along line 2--2ofFlg.1; l

Fig. 3 is a horizontal section taken along line Fig. 4 is a vertical transverse section taken along line H 01' Fig. 2;

Figs; 5 to 8 inclusive are somewhat conventionalized figures illustrating a complete cycle in the formation of a stitch formed from mecha- Fig. 1 is a iragmentaryelevaticn of the closure portion of a bag including a line of stitches along line II5 of Fig. 14;

nisms constructed in accordance with this invention; Fig. 9 is a fragmentary detailed elevation with parts in section taken along line 9--9 of Fig. 5;

Fig. 10 is a fragmentary detailed elevation with parts in section taken along lin Ill-I8 of Fig. Fig. 11 is a fragmentary detailed elevation with parts in section taken along line "-4 I of Fig. "I; Fig. 12 is a fragmentary detailed elevatio with parts in section taken along line I2I2 of Fig. 8;

Fig. 13 is a motion diagram showing the movement of the auxiliary looper and indicating the paths of travel of the needle and the binder thread loop receiving fork;

Fig, 14 is an elevational view of a sewing machine including mechanisms constructed in accordance with this invention, the view being partially in section since portions of the mechanism shown in Fig. 16 have been broken away;

with an eccentric 2I which serves to impart a combined oscillatory and reciprocatory mo eent to the element I9. The eccentric 2| is mounted on one end of a shaft 22 journalled on the bracket I6 and is adapted to be driven through connections which include a lower set of bevelled gears generally indicated at 23, a vertical shaft 24 and an upper set of bevelled gears generally indicated at 25. The upper bevelled gears 25 are adapted to be driven from the main drive shaft Ia through the medium of an auxiliary drive shaft 26 disposed in substantial parallelism therewith and operatively connected thereto through the medium of spur gears generally indicated at 21. The free end of the looper lcarrying element I9 is provided with an auxil- Fig. 15 is a transverse vertical section taken v Fig. 16 is a horizontal section taken along line I6-I6 of Fig. 14 and showing certain mechanism which has been broken away from Fig. 14.

Fig. 1'7 is an elevational view of the mechanism shown in Fig. 16 taken in a direction normal to the axis of the auxiliary. looper elements; and

Fig. 18 is a fragmentary vertical section taken along line I8l8 of Fig. 16.

Referring to the drawings in detail, the mvention, as illustrated, is embodied. in a sewing machine of the type disclosed in the above-mentioned United States Letters Patent 2,043,149 and includes a main frame comprising a standard 5, an upper horizontal portion 6 and a depending post portion I spaced from the standard 5 to thereby completely define an inverted generally U-shaped frame. The horizontal portion 6 of the frame operatively houses the usual drive shaft Ia and associated driving pulleys generally indicated at 8. The drive shaft is operatively connected with the various elements which are normally effective to form a simple two-thread chain stitch in the manner clearly disclosed in the aforementioned United States Letters Patent 2,043,149 and which include a work support 9 secured on the inner face of the standard 5 adjacent the lower end thereof and feed dogs I0 associated therewith. A presser foot II is disposed in opposed relation to the work support 9 and is adapted to cooperate with the feed dogs in feeding of the work between the presser foot and the work support. The usual needle I2 is slidably mounted for lateral reciprocation on the lower end of the post I and has its axis aligned substantially normal to the general plane defining the work support. The main looper element I3 is oscillatibly mounted in the lower end of the standard 5 in the usual manner and is adapted to cooperate with the needle I2 in forming a two-thread chain stitch. A needle thread I4 is threadably engaged in the needle I2 and a looper thread I5 is threadably engaged with the main looper I3 in the well known manner.

The lower end of the post I is provided with an offset bracketIIi. including a bar portion I'I inclined relative to the axis of the needle I2. The

forward end of the inclined bar I! of the bracket cooperate with the auxiliary looper element 28 in forming the loops of an auxiliary binder thread 36 threadably engaged with the auxiliary looper The roller cam follower 32 is operatively engaged with a cam 31 rigidly secured to the shaft 24 and effective to impart an oscillatory movement to the arm 3I and consequently to the loop forming fork element 34. Preferably, the arm 3| is spring biased against the cam 31 in order that contact therewith may be satisfactorily maintained, and the desired motion may be imparted to the fork 34 in a uniform manner.

Thus, it will be readily apparent that rotation of the main drive shaft Ia and its associated driving connections will effect the combined oscillation and reciprocation of the looper mounting element I9- and consequently eifect movement of the auxiliary looper 28 through a generally elliptical path, a portion of which overlies the axis along which the needle I2 travels. Simultaneously with the movement of the looper element 28 the loop forming fork 34 will be oscillated laterally as a result of the driving connections between the cam 31 and the cam follower 32 mounted on the rock arm 3|. The combined motions of the fork 34 and the looper 28 serve toform the auxiliary binder thread 36 into successively formed loops, the centers of which are disposed in coaxial relationship with the needle I2 prior to the time at which the needle penetrates the work preparatory to the beginning of a stitch.

In Figs. 5 through 8 of the drawings, there is illustrated the manner in which the various structural elements above described function to form a line of stitches. In Fig. 5 the needle I2 together with the auxiliary loop forming fork 34 and the auxiliary looper 28 are shown in their proper relative positions during the first stage of a stitch formation, the needle being at the beginning of its retractive stroke. In Fig. 6 the needle I2 has been retracted from engagement with the work W and the main looper I3 has been projected through the loop of the needle thread I4. At this stage of the cycle of stitch formation the auxiliary looper element 28 has moved upwardly and forwardly to the left to engage the binder thread 36 around the bifur- V m m 3 H mer ar e -means:

was a other raw, as move fr m the posltionfshown in mg. '1: toward s ed wesome mason. p scraper-aw y m s downwardly .between th iiiljid igthre. fad, thousands.

The auxiliarylooperll moves out'oi" the path offlthe needle' 'fjl'l in timejfor the needle "to pass through the loop while it isheld by meters 341 and thereafter, the. fork It moves out of the path of the needle 12 towards theposltion illustrated in H8. 8. 'In Figriithe feed step of the work through the machine has been completed and the needle II has been propelled through the loop formed in the binder thread I. and is ready to pierce the work for the formation of another stitch. Figs.'9,'10,1-1.and 12 of the drawings are elevational views which respectively correspond to Figs. 5, 6, 7 and 8 and more .clearly show the exact manner by which a loop is formed in the binder thread it It should be noted that the lateraloscillation of the loop forming fork It is so timed that it, eifects the disengagement thereof from thebinder thread 36 subsequent to the engagement ofthe needle 12 within the loop formed in the thread 36 and to position the loop forming fork in its proper location to be again engaged by the binder thread preparatory to the formation of the next succeeding stitch. It should be further noted that by disposing the elliptical path of travel of the auxiliary looper 28 in a plane inclined to the path of travel of the needle I: there is no necessity for providingmore than Just a two-motion movement to the auxiliary looper II as effected through the medium of the eccentric and strap connections. i

Fig. 13 is .a motion diagram corresponding generally to Figs. 5, 6, 7 and 8, showing the path of travel IIAof the auxiliary looper II and indicating at 34A and 12A, respectively, the paths 'of travel of the fork 34 and needle l2.

Figs. 1 to 4 of the drawings, inclusive, illustrate fragmentary portions of a complete line of the stitches, as applied to the closure seam of a filled paper bag or the like, and formed by the herein described mechanisms. It will be noted that the needle and looper threads together define a plurality of serially formed concatenated loops on the work support side of the seam. The needle side of the seam presents the normal appearance of a series of through and through stitches and, in addition, is provided with the auxiliary or hinder thread 36 which is formed into a plurality of spaced connected loops which encompass the base portions of the respective needle thread loops on the needle side of the a s'utsanuwmna uzanmnsq asse .s" e

cated end I! of the loop forming fork 84. "on the other side of "the-seam to thereby .p j videabag'closureseam which is substantially sifiiirtfiti n's ur Itis re if mare ws w n mmi wars in connection th the closing of-iilledgpaper bags which have v fnot heretofore been provided can t e b Warh ad s tch arms portions off thefmeedlethreadloopsi d d thus substantially] the needle apertures en the needle Side of thework, and the concatenations of theneedleand looperthreads effectively sealthe needle apertures on the fw'orkjsupport side; of the :wo'rkfand a substantially siftproof seam is thereby produced "Since theherein disclosed mechanism effects the formation ofth'e binder thread it into a series of spaced loops joined'by connecting thread portions, the whole of which lies flat against the adjacent, surface of the work, any pull or strain tendingto compact the needle thread and looper thread portions of the stitches together will be resistedby the tensile strength .of the binder thread 36. Thus, the formed stitches cannot collapse or' be drawn together without first breaking the binder thread. Furthermore, the provision of thebinder thread in the manner illustrated tends to prevent rupturing of the stitch formation as a result of tearing of the bag materialbetween adjacent needle holes under imposed strains. Preferably, the binder thread 36 during the stitch forming operations is drawn under the same degree oftension as the looper and needle threads in orderthat all slack maybe fully taken up at the end of the formation of each stitch.

Thus, it will be seen that the herein disclosed invention provides novel improvements in a sewing mchine which are effective to form a stitch of the double thread chain stitch type employing a binding thread serially formed into a plurality of spaced .oops located upon the needle side of the work and encompassing the base portion of each needle thread loop, in which the binding thread loops are formed by a pair of cooperatively disposed loop forming elements located on the needle side of the machine, and which is simple in design', rugged in construction and economical to manufacture.

It is of course to be understood that certain details of arrangement and proportions of parts may be variously modified without exceeding the for forming a binder threadinto ,a plurality'of" spaced connected loops, each of said loops being formed at the beginning ofa cycle of stitchformation whereby in the completed line of stitches in a position encompassing the path of travel of said needle until said needle has entered said binder thread loop, the movement of said loop receiving means away from said position releasing each successively formed binder threadlooD for encompassing engagement with a needle thread loop.

2. In a sewing machine, a work support, a presser foot opposed to said work support, means to feed work between said work support and said presser foot, a reciprocatory threaded needle having its axis disposed substantially normal to the general plane of said work support, a threaded looper cooperatively disposed with respect to said needle, means for cyclicly moving said feed means, said needle and said looper for forming a line of stitches including concatenated needle thread and looper thread loops on the work support side, and means oper'atively connected with said moving means for serially forming a binder thread into a plurality of spaced connected loops located on the needle side of the work, said means for forming said binder thread into a plurality of spaced connected loops comprising an auxiliary looper, loop receiving means, and means to move said loop receiving means into and out of a position wherein it is adapted to receive a loop of binder thread formed by said auxiliary looper and to support said loop in a position encompassing the path of travel of said needle until said needle has entered said binder thread loop, the movement of said loop receiving means away from said position releasing each successively formed binder thread loop for encompassing engagement with a needle thread loop.

3. In a sewing machine, a work support, a presser foot opposed to said work support, means to feed work between said work support and said presser foot, a reciprocatory threaded needle having its axis disposed substantially normalto the general plane of said work support, a threaded looper cooperatively disposed with respect to said needle, means for cyclicly moving said feed means, said needle and said looper for forming a line of stitches including concatenated needle thread and looper thread loops on the work support side, a fork movable into and out of the path of travel of said needle, an auxiliary looper cooperatively disposed with respect to said fork and adapted to form a loop of binder thread therearound while said fork is positioned in the path of travel of said needle to thereby define a binder thread loop adapted to receive each needle thread loop as it is formed and encompass the base portion thereof, and means to actuate said fork and said auxiliary looper in timed relation with respect to said needle.

4. In a sewing machine of the class described,

-a fork movable into and out of the path of a threaded reciprocable needle, 8, looper cooperatively disposed with respect to said fork and adapted to form a loop of binder thread therearound while said fork is positioned in the path of travel of said needle, said binder thread loop being adapted to receive a needle thread loop and encompass the base portions thereof, and means to impart loop forming movements to said fork and said looper in timed relation relative to the "movement of said needle.

5. In a sewing machine of the class described, a fork movable into and out of the path of a threaded reciprocable needle, means including a cam actuated rock arm for moving said fork, a looper cooperatively disposed with respect to said fork and adapted to form a loop of binder thread therearound while said fork is the path of travel of said needle, saidbinder thread loop'being adapted to receive a needle-thread loop and encompass the base portions thereof,

and means for moving said looper through a gen erally elliptical path enclosing said fork. .whlle said fork is positioned in the path of travel of said needle to thereby form said binder thread 00p. v 6. In a sewing machine of th class described. a movable fork disposed to one side of a reciprocatory needle, means for moving said fork into and out of the path of said needle, a looper disposed on the other side of said needle,- said looper being adapted to form a loop of binder thread around said fork while said fork is positioned in the path of travel of said needle, and means for moving said looper through a generally elliptical path enclosing said fork while said fork adapted to form a loop of binder thread around said fork while said fork is positioned in the path of travel of said needle, and means for moving said looper through a generally elliptical path enclosing said fork while said fork is positioned in the path of said needle to thereby form-said binder thread loop in position to receive a needle thread loop and encompass the base portion thereof.

8. In a sewing machine of the class described, a movable fork disposed to one side of a reciprocatory needle, means including a cam actuated rock arm for moving said fork into and out of the path of said needle, a looper disposed to the other side of said needle, said looper being adapted to form a loop of binder thread around said fork while said fork is positioned in the path of travel of said needle, and means including eccentric and strap connections for moving said looper through a generally elliptical path enclosing said fork while said fork is positioned in the path of said needle to thereby form said binder thread loop in position to receive a needle thread loop and encompass the base portion thereof.

9. In a sewing machine of the class described, a fork movable into and out of a position in which aloop formed upon the prongs thereof encompasses the path of travel of a threaded reciprocable needle, a looper cooperatively disposed with respect to said fork and adapted to form a loop of binder thread around the prongs thereof while said' fork is in said position, said binder thread loop being adapted to receive a needle thread loop and encompass the base portions thereof, and means to impart movement to said thread loops, the combination of loop receiving v means movable into and out of a position in which a loop received thereby encompasses the bath of travel of said needle on the needle side of the work, a looper cooperatively disposed with respect to said loop receiving means and adapted to form tor reciprocatingsaid needle to form needle thread loops, the combination of loop receiving means, means for moving said loop receiving means into and out of the path 'of said needle, a

a loop of binder thread thereupon whilesaid loop receiving means is in said position, said binder thread loop being adapted to receive a needle thread loop and encompass the base portions thereof, and means to impart movement to said looper adapted to form a loop ot'binder thread around said loop receiving means when the same is positioned in the path ot-travel of said needle, means for moving said looper in a pathencompassing said loop receiving means when the same is in the path of travel of the needle and encompassing the path of travel ofsaid needle,

and means for operating the needle reciprocating. means, the moving means for said loop receiving means and the looper moving means in such timed relation as to form a loop of said binder thread in position to receive said needle as the same moves toward the work and to remove said loop receiving means from the path of said needle whereby to release said binder thread loop for encompassing engagement with the needle thread loop formed by said needle.

, HARRY E. CLAYTON. 

